From: lkcl Date: Sat, 19 Dec 2020 18:26:46 +0000 (+0000) Subject: (no commit message) X-Git-Tag: convert-csv-opcode-to-binary~1175 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d2cb92c8d626ddd962e40cef80900235f0a74f43;p=libreriscv.git --- diff --git a/openpower/sv/svp_rewrite/svp64.mdwn b/openpower/sv/svp_rewrite/svp64.mdwn index 2003722f7..dd4597f8d 100644 --- a/openpower/sv/svp_rewrite/svp64.mdwn +++ b/openpower/sv/svp_rewrite/svp64.mdwn @@ -441,6 +441,8 @@ CR element*. Greatly simplified pseudocode: If a "cumulated" CR based analysis of results is desired (a la VSX CR6) then a followup instruction must be performed, setting "reduce" mode on the Vector of CRs, using cr ops to do so. This provides far more flexibility in analysing vectors than standard Vector ISAs. Normal Vector ISAs are typically restricted to "were all results nonzero" and "were some results nonzero". The application of mapreduce to Vectorised cr operations allows far more sophisticated analysis. +Note in particular that the use of a separate instruction in this wat ensures that high performance multi-issue OoO inplementations do not have the computation of the cumulative analysis CR as a bottleneck and hindrance, regardless of the length of VL. + (see [[discussion]]. some alternative schemes are described there) ## Table of CR fields